Have you ever come across this error?
Invalid Regular period. You must specify values for the A3, P3 and T3 parameters for a subscription.
It's because Paypal sets limits to the lengths you're allowed to set for subscriptions that have recurring billing. In vBulletin, for example, this limitation is not mentioned in the admin back-end. (Admittedly, I've not scoured the vBulletin user manual, but I'd think this info would have been important enough to put in the subscription setup area)
- D – for days; allowable range for p3 is 1 to 90
- W – for weeks; allowable range for p3 is 1 to 52
- M – for months; allowable range for p3 is 1 to 24
- Y – for years; allowable range for p3 is 1 to 5
So you can only have subscriptions on cycles with a maximum value of 90 days, 52 weeks, 24 months, or 5 years.
My recent attempt to create a subscription for longer than 24 months failed. This does not appear to affect one-time payments, as I was able to create 10-year subscriptions that was not recurring.
Lowered my values, and it should work. Easy enough!
Information from docs found at x.com, the Paypal Developer Network.